It has been known that deposits are formed on the surface of fuel injectors of gasoline engines and diesel engines and on the surface of carburetors and intake valves of the gasoline engines by the oxidation of the fuel and lubricant oil.
These deposits even in a relatively small amount can cause severe drive-ability problems such as misfire and poor acceleration. Moreover, the engine deposits can significantly increases an automobile's fuel consumption and production of exhaust pollutants.
Under these circumstances, aliphatic amine compounds based on a long chained hydrocarbon have been developed and used as a detergent for the fuel to prevent or inhibit the formation of such deposits. U.S. Pat. No. 3,438,757 and U.S. Pat. No. 3,574,576 disclose that hydrocarbyl amine having a molecular weight of 425.about.10,000, preferably 450.about.5,000 is useful as a detergent for the fuel of internal combustion engine or as a dispersant for the lubricant oil.
However, chlorine compounds which are employed in the process for the preparation of the hydrocarbyl amine are remained in the detergent. When such a detergent is used in addition to the fuel, the corrosion of the engine and the exhaustion of hazardous gas increase.
European Patent No. 476485 A discloses that polybutylaminoalcohol produced by reacting amine with polybutene epoxide obtained by the epoxidation of polybutene is useful as a detergent for the gasoline and as a additive to the lubricant oil. The polybutylaminoalcohol is produced by a nucleophilic substitution reaction of polybutene epoxide with amine.
However, since the molecular weight of polybutene is too large and the double bond linkages thereof have too many substitutions of alkyl, the polybutene epoxide produced therefrom exhibits a low reaction rate by the steric hindrance so that the polybutene epoxide would be subjected to the reaction with amine for a long period of time to produce polybutylene aminoalcohol. Thus, the effect to prevent the formation of deposits on the intake valve of the gasoline engine would have a little actual effect.